Audiovisual telecommunication method and apparatus using a digital network

ABSTRACT

A videoconferencing network of audiovisual communication terminals is interconnected by a telephone network. Each terminal is activated only when the balance in a user account has been read and the account has been made available for debiting. The terminal includes a monitor system for playing out and receiving voice and picture information, an interface system for conditioning signals passing between the monitor system and the telephone network, and a database which contains the locations and telephone numbers of other terminals of the videoconferencing network. The terminal further includes a display of information from the database, a pointing device by means of which a user can make a selection from the display by indicating the relevant position in the display, and a device for automatically dialing up the selected remote terminal.

FIELD OF THE INVENTION

This invention relates to teleconferencing terminals and networksthereof. More specifically, the invention relates to audiovisualteleconferencing terminals that can be interconnected via publicallyaccessible, digital, telephone networks.

ART BACKGROUND

The public has long enjoyed the convenience of coin-operated orcard-operated public telephones. These devices have made it possible forcustomers to place telephone calls when business or travel takes themout of their homes, or when their homes are not equipped with telephonesets.

The same is not true of videoconferencing terminals. Although there is asubstantial demand for videoconferencing services, terminal equipmentfor this purpose has been, and remains today, concentrated in narrowmarkets.

In the 1960s and 1970s, AT&T PICTUREPHONE visual telephone serviceprovided audiovisual communication between publicly accessibleinstallations. However, this service was not widely available, and wasinconvenient to use, largely because it lacked a high level ofautomation. In the 1970s and 1980s, AT&T provided a PICTUREPHONE meetingservice. This service suffered some of the same disadvantages as theearlier PICTUREPHONE service, and was not generally available to thepublic.

Currently, AT&T provides a standard teleconferencing service, intendedmostly to serve businesses. This service overcomes many of thedisadvantages of the earlier PICTUREPHONE services, but does not resultin facilities that are available to the general public, and is beyondthe economic reach of most individual consumers.

The advent of desktop video systems has made it possible for privateindividuals to participate in teleconferencing. However, privatevideoconferencing products and services call for service fees and aninvestment in equipment that substantially exceed the costs of ordinarytelephone services. Thus, even the current generation of desktop videois not attractive to the consumer who would be only a casual orincidental user of teleconferencing services.

Thus, until now there has lacked a videoconferencing facility, generallyavailable to the public, for making a two-way, audiovisual call betweengenerally accessible locations at a modest, one-time cost.

SUMMARY OF THE INVENTION

We have provided such a facility. In a broad sense, our inventioninvolves a videoconferencing network of audiovisual communicationterminals interconnected by a telephone network. Each terminal isactivated only when the balance in a user account has been read and theaccount has been made available for debiting. The terminal includes amonitor system for playing out and receiving voice and pictureinformation, and an interface system for conditioning signals passingbetween the monitor system and the telephone network. The terminalfurther includes a database which contains the locations and telephonenumbers of other terminals of the videoconferencing network. Theterminal further includes a display of information from the database, apointing device by means of which a user can make a selection from thedisplay by indicating the relevant position in the display, and a devicefor automatically dialing up the selected remote terminal.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a block diagram of a communication network according to theinvention in one aspect.

FIG. 2 is a block diagram of a card-activated communication terminalaccording to the invention in one embodiment.

FIG. 3 is a block diagram of an illustrative communication interface.

FIG. 4 is a block diagram of an administrative office in communicationwith a terminal, according to the invention in one embodiment.

FIG. 5 is a block diagram of a communication network according to theinvention in one embodiment, including a telephone for use in makingreservations.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

Turning to FIG. 1, the invention in one aspect is a network 5 ofaudiovisual teleconference terminals 10, interconnected by a publicswitched telephone network (PSTN) 20. In order to assure that there issufficient capacity to carry audio and video communication signals, itis desirable for public network 20 to provide ISDN service, or theequivalent, between each terminal and its local exchange.

For convenience in charging for calls, it is advantageous for publicnetwork 20 to be configurable so as to define the network 5 ofteleconference terminals (hereafter, the "T/C network") as a virtualprivate network (VPN) such as a software-defined digital network (SDDN).

A VPN is a carrier-provided service that emulates a network of privatelines, but is designed logically within a public network. VPN servicesare commercially available from common carriers in thetelecommunications industry. For example, AT&T provides asoftware-defined network intended primarily as a communication servicefor businesses having multiple locations and unique communicationrequirements. In such a service, information for processing telephonecalls is stored in a database, and this database is accessed during eachcall. Brief descriptions of this technology may be found in Newton'sTelecom Dictionary, Flatiron Publishing, Inc. (1994), pp. 957-958 and1123-1124. A particular implementation of VPN technology is described inU.S. Pat. No. 4,348,554, issued to R. Asmuth on Sep. 7, 1982.

The virtual private network arrangement makes it possible for thebilling for use of the PSTN to be directed to a central serviceprovider. This provider can arrange to be paid back by, for example,selling debit cards to its customers. These cards can, in turn, be usedto activate the terminals 10 at the expense of charge accounts stored onthe cards.

Such a card-activated system is depicted in FIG. 2. As shown in thatfigure, card reader 30 operates element 40 for activating the terminalso that it will communicate with and respond to a user. In our currentlypreferred embodiment, the activation function of element 40 isimplemented in software which resides in computer 50.

One type of card useful in this context is a Smartcard, whichincorporates a solid-state memory chip. Such a card is readily prepared,for sale to users, by storing in the memory a decrementable record ofthe number of monetary units remaining in a prepaid account.Advantageously, each card also stores a serial number unique to thatcard.

By way of example, the card remains in the card reader during the entireduration of the teleconferencing call (hereafter, simply, the "call").Monitor 60, which includes a display screen such as a CRT screen, warnsthe user when the debit account is approaching exhaustion. Optionally,the screen may display a periodic or continual notice of time remainingin the account. At the end of the call, the account balance is updatedand recorded in the card. The rate at which the card is debited can bemade dependent upon the type of call. For example, a database includedin the terminal stores the telephone numbers of terminal locations innetwork 5. (Optionally, this database also stores the telephone numbersof terminals that are not part of the private network, but are owned orcontrolled by parties who have indicated that they wish to subscribe tothe database so that they can be dialed up automatically and reached viathe PSTN. Such terminals are referred to herein as "off-net" terminals.)In association with each stored telephone number, a charging rate isalso readily stored. Thus, for example, local, domestic long distance,and international calls can be charge the debit card at distinct rates.

We currently envisage that only the originator of the call will bedebited for the call, but as an optional feature of the invention, eachparty may be required to insert his card into an external card reader inorder to gain access to the terminal, exemplarily by unlocking the doorto a booth.

Alternative debitting schemes are readily apparent and are intended tofall within the scope of the invention.

For example, the owner of the premises where each terminal is locatedmay charge a fee for the user of his premises. Such fees may be deductedfrom the cards at both ends.

As noted, computer 50 is in communication with card reader 30. Computer50 performs the metering of calls for billing purposes, and directs cardreader 30 to debit the card accordingly.

Each terminal 10 also includes a database 70 which lists the locationsand telephone numbers of the other terminals of T/C network 5. Thisdatabase will typically reside within computer 50, as will thefunctionality, represented in the figure as element 80, for retrievingdata from, and storing data in, the database.

In order to simplify the use of the terminal, it is advantageous toinclude an autodial functionality 90, which will also typically residewithin the computer. This functionality will automatically dial up(i.e., enter the telephone number of) the destination terminal, in orderto made the desired telephone connection. A simple, manual action by theuser will indicate the selected terminal location that is to be dialedup.

For example, our currently preferred embodiment includes atouch-activated surface which includes a computer-driven, graphicaldisplay device. The display device is exemplarily a VGA/SGA monitor, andmay be identical with the display device of monitor 60. Alternatively, aseparate device having touch-activation and display functions isprovided. Such a separate device is shown in the figure as touchpad 100,which exemplarily incorporates a liquid crystal display (LCD) driven bycomputer 50.

A succession of fields containing selections of narrowing scope arepresented on the touch-activated display device, such as a choice ofcontinents, followed by a choice of countries within the selectedcontinent, followed in like manner by regions, cities, and pointlocations. Each field is displayed as an array of shapes, or icons. Theuser indicates his choice with the touch of a finger on the desiredshape or icon.

Alternatively, the various locations are displayed in the form of mapswhich change in scale as the selection is narrowed down. Each successiveselection is indicated by touching a map region, or an icon superimposedon a map.

Significantly, both terminal locations that are part of the privatenetwork, and "off-net" locations, can be indicated in these displays.

The first field also includes a touchable symbol for the "manual dial"option. If this option is selected, the next field to be displayed is arepresentation of a telephone keypad, for receiving the manually-enteredtelephone number.

It is desirable for each field after the first one to include a "goback" icon.

Advantageously, at least some of the fields also include an audio volumecontrol (represented, e.g., by a bar or series of gradations) and astart call/stop call button. Initially, this icon appears as a "start"button, to be touched in order to initiate the autodial function. Oncethe call has been placed, the word "start" changes to "stop," andtouching of this icon then terminates the call which is in progress.These functions are performed by computer 50 which, as noted, is incommunication with the touchpad.

Monitor 60 includes a video camera and microphone for receiving localaudiovisual information, and a screen and loudspeaker for reproducingremote audiovisual information.

Input and output signals pass to and from the monitor via thedata-handling functionality designated as element 110 in the figure.This functionality is typically provided by computer 50.

The data passing between terminal 10 and telephone network 20 aremediated by communication interface 120. This communication interfaceconditions the incoming and outgoing signals, which carry audioinformation, video information, and digital data, so that these signalscan be exchanged between the computer and monitor, on the one hand, andthe telephone network on the other hand.

A currently preferred embodiment of interface 120, as shown in FIG. 3,includes BRI interface card 130 and NT-1 network terminal interfacedevice 140. As noted, the local facilities network should provide ISDNservice in order to transmit the full range of signals passing throughinterface 120. Preferably, the local facilities network includes a BRIline 150 to interface 120, because such a line has the capacity to carry128 kbit/sec video signals. As shown, the BRI line is connected to theNT-1, which performs digital-to-digital data conversion. The NT-1, inturn, is connected to BRI interface card 130.

Turning back to FIG. 2, our current implementation of terminal 10 isbuilt around the commercially available AT&T VISTIUM® System. The basicsystem includes a P-5 computer system, an audio system, a keyboard, anNT-1, a 14.4 modem, a 1300 system board, a BRI card, and otherperipheral components. The touchpad 100 is similar to a touch-sensitiveLCD screen that is commercially available from the Phoenix Group, Inc.Suitable cards and card readers are commercially available, exemplarilyfrom GEMPLUS Card International Corp., 656 Quince Orchard Rd., Suite610, Gaithersburg, Md. 20878.

The video display portion of monitor 60 is preferably a video monitorthat uses NTSC protocols. If necessary, such a monitor can be made tooperate at reduced resolution so that it is controllable at the samedata rate as a (lower resolution) LCD touchpad.

When the P-5 computer system is used, it is advantageous to control boththe video monitor and the touchpad from a single controller card, whichis modified, if necessary, to provide a compatible port for connectionto the touchpad.

It is desirable for terminal 10 to be enclosed within a booth forprivacy and isolation from visual and acoustic distractions. Such a bothis conveniently provided in the form of, e.g., a fiberglass shell havinga lighting and ventilation system. The light level is optionallycontrolled by way of a further icon displayed in at least some of thefields of touchpad 100.

Turning back to FIG. 1, network 5 also desirably includes administrativeoffice 160. This office will typically include at least some of thesame, or similar, components as each of the terminals 10, such ascomputer 50, database 70, and interface 120. Information about thestatus, location, and telephone number of each of the terminals 10, andoptionally, also information about card serial numbers known to befraudulent, is initially stored in the database at the administrativeoffice.

As shown in FIG. 4, this information is transmitted over network 5 toeach of the terminals, together with a digital sequence that identifiesit as administrative information. Upon recognition of this sequence theinformation is read into database 70 at each terminal.

Conversely, each terminal locally stores information about the use ofthat terminal. This "use" information includes the serial number of eachcard used to initiate a call, the duration of each call, and thedestination of each call. When a request is initiated by an appropriatecode sequence from the administrative office, the computer at the calledterminal reads the "use" information out of its local database and sendsit to the administrative office.

A further function optionally performed by the administrative office 160is the implementation of a reservation system. To arrange for areservation, a customer contacts the administrative office via telephone170 or other suitable communication device (see FIG. 5). Through a humancustomer representative or through a computer at office 160, asappropriate, the customer specifies a timeslot and two or more terminallocations that are to be connected. Office 160 then sends thesetimeslots to the reserved terminals as administrative information, andoptionally also sends information about premium billing for thisservice.

At each local terminal, this administrative information is used to set acalendar function that informs the local computer when a reservedtimeslot is approaching. This is achieved, for example, by having thecomputer consult a locally stored record of reserved timeslots everytime a user attempts to activate the terminal.

If a user does, in fact, attempt to activate a terminal within apredetermined margin, such as one hour, before the beginning of areserved timeslot, the monitor will display a warning message thatavailable time is limited. If the user nevertheless proceeds with acall, the monitor will display at least one further warning messagebefore the call is terminated by the local computer.

It is advantageous for the reserving party to submit his card serialnumber at the time the reservation is made. This information will thenbe sent to the local terminals along with the other information aboutthe reservation. This identification number can be matched against theserial number actually used to activate the terminal to make the call.The call will be authorized only if the serial numbers agree.

A similar authorization procedure can be implemented with respect to theserial number of the debit card that belongs to the party who is toreceive the call. However, in many cases it may be unnecessary for thereceiving party to use a card

Optionally, the call can be automatically set up at the start of thereserved timeslot without the need for the calling party to manuallyselect his destination. The calendar information referred to above can,e.g., trigger an instruction to load the pre-arranged receivingtelephone number into the terminal's autodial facility at the beginningof the reserved timeslot.

The above discussion has mostly addressed two-party calls. However, itshould be noted that multiple-party calls are as readily made using theinventive network. This is done using appropriate transmission equipmentat the local terminals 10. Alternatively, multiple-party calls are madeby routing calls through a commercial teleconference service having amultipoint video bridge. Such a service is the AT&T Video GO Center.

The invention claimed is:
 1. A network of audiovisual communicationterminals interconnected by a communication medium, wherein eachterminal comprises:a) a monitor system for playing out and receivingvoice and picture information, the monitor system including a displayscreen, the monitor system further including a microphone and videocamera for video teleconferencing; b) a card reader adapted to activatethe terminal only after reading the balance in an account on a debitcard; c) a communication interface device that conditions, forreception, audiovisual signals from others of said terminals that passto the monitor system via the communication medium, and that conditions,for transmission, audiovisual signals to be sent to others of saidterminal via the communication medium; d) a dial-up device adapted tomake contact with at least one specified other of said terminals; e) adestination database at least of some other of said terminals; f) aninformation-retrieval device adapted, upon request, to retrieve from thedestination database information about others of said terminals and,responsive to the retrieved information, to display on the screen aselectable listing of other terminals to which contact may be made; g) auser-activated selection device adapted to automatically direct thedial-up device to make contact with a terminal selected by a user fromthe displayed listing; and h) an administrative office interconnectablewith each of said terminals, an administrative database included withinthe administrative office, and means for sending data from theadministrative office to each said terminal and storing said data ateach said terminal, wherein said administrative database comprises aschedule of reserved timeslots for designated terminals, and saidsending and storing means are adapted to transfer, from said schedule toeach of the designated terminals, reservation information pertaining tothe respective timeslot reserved for that terminal.
 2. Apparatus ofclaim 1, wherein the card reader is further adapted to reduce saidbalance, and record the reduced balance on the card, after a call hasoccurred between at least two said terminals.
 3. Apparatus of claim 1,wherein the communication medium is a public telephone network. 4.Apparatus of claim 1, wherein the user-activated selection devicecomprises a touch-sensitive display device.
 5. Apparatus of claim 1,wherein the destination database contains information relating to thelocations of other terminals of the network, and the selectable listingis displayed on the screen in the form of at least one map.
 6. Apparatusof claim 5, wherein the information-retrieval device is adapted todisplay the listing as a large-scale map, and, responsive to theselection device, at least one map selected from a plurality ofsmaller-scale maps.
 7. Apparatus of claim 5, wherein the network is asoftware-defined digital network, and the destination database furthercontains information relating to the locations of terminals that are notpart of said network, but can be selected by the use of theuser-activated selection device and accessed by the dial-up device. 8.Apparatus of claim 1, whereina) the communication medium is a publictelephone network; and b) the public telephone network comprises meansfor defining the interconnection of said terminals as a private network.9. Apparatus of claim 8, wherein the private network is asoftware-defined network.
 10. Apparatus of claim 9, wherein the privatenetwork is a digital network.
 11. Apparatus of claim 1, wherein eachterminal is enclosed within a booth, the booth includes a light sourceand a light-level controller for regulating the light source, and theuser-activated selection device is adapted to activate the light-levelcontroller at the option of a user of the terminal.
 12. Apparatus ofclaim 1, wherein each debit card has a serial number, and each terminalfurther comprises:a library of invalid serial numbers; and means forcomparing the serial number of each user's card with said library,thereby to verify that said card is valid before the terminal isactivated.
 13. Apparatus of claim 1, wherein the destination databasecontains information relating to the locations of other terminals on thenetwork, and the selectable listing is displayed on the screen in theform of a plurality of icons.
 14. Apparatus of claim 1, wherein thenetwork is a software-defined digital network, and the destinationdatabase contains information relating to terminals that are not part ofsaid network, but can be accessed by the dial-up device.
 15. Apparatusof claim 1, wherein said administrative database comprises a library ofdestinations that are intended to be accessible by the dial-up device ateach terminal, and the storing means are adapted to store informationabout said destinations in the destination database at each saidterminal.
 16. Apparatus of claim 1, wherein:each debit card has a serialnumber; each terminal comprises a look-up library of invalid serialnumbers and means for comparing the serial number of each user's cardwith said library, thereby to verify that said card is is valid beforethe terminal is activated; said administrative database comprises acentral library of invalid serial numbers; and said sending and storingmeans are adapted to transfer invalid card information from the centrallibrary to each look-up library.
 17. Apparatus of claim 1, wherein eachdesignated terminal is a call-originating terminal or a destinationterminal, and the reservation information to be transferred to eachdesignated, call-originating terminal includes a telephone number thatis to be automatically dialed up.
 18. Apparatus of claim 1, wherein eachterminal further comprises means, responsive to transferred reservationinformation, for denying use of said terminal, during a reservedtimeslot, for any call but a call identified in said transferredinformation.
 19. Apparatus of claim 18, wherein said denying means arefurther adapted to deny use of said terminal, during a reservedtimeslot, to any call-originating party but a party whose debit cardserial number matches a serial number provided in said transferredinformation.
 20. A method for placing an audiovisual telephone call froma designated sending location to a designated receiving location at therequest of a user who possesses a debit card, wherein the call isreserved for a designated timeslot and for said designated locations,the method comprising:a) before enabling the call to be made, comparingthe instant time and date with reservation information in a database atthe sending location, thereby to verify that the reserved timeslot hasbegun; b) before enabling the call to be made, reading an accountbalance from the card, thereby to verify that there is a sufficientpositive balance; c) receiving from the user a designation of thereceiving location, and, responsive to said designation, retrieving abilling rate and a destination telephone number from said database atthe sending location; d) automatically dialing the retrieved destinationtelephone number, thereby to establish connection between the sendingand receiving locations at least partly over a software defined digitalnetwork; e) if the automatic dialing step results in a connectionbetween the sending and receiving locations, bidirectionallytransmitting digital audiovisual data between said locations for theduration of any resulting telephone call; and f) debiting the accountrecorded in said card in accordance with said billing rate and saidduration.
 21. The method of claim 20, further comprising, beforeenabling the call to be made:reading a serial number from the debitcard; and comparing the serial number to a list of serial numbers in adatabase at the sending location, thereby to verify that the debit cardis valid.
 22. The method of claim 20, wherein the step of receiving adesignation of the receiving location is carried out by:displaying aselection of geographical locations on a touch-sensitive graphicaldisplay device; and receiving a signal generated when the user touches aselected portion of the geographical display.
 23. The method of claim22, wherein the displaying step comprises displaying a sequence offields, each field containing geographical information of greater detailthan the preceding field, and each field after the first is displayed inresponse to a designation made by the user by touching a portion of thepreceding field.
 24. The method of claim 22, wherein the displaying stepcomprises representing geographical information in the form of at leastone user-designatable icon.
 25. The method of claim 22, wherein thedisplaying step comprises representing geographical information in theform of at least one map having at least one user-designatable portion.